1. Field of the Invention
This invention relates to a resiliently tiltable load supporting base for vehicle jacks.
2. Description of the Prior Art
The mechanical advantage of the vehicle jacks is usually obtained by screw, lever or hydraulic action. Thus, the screw jack has a threaded screw fitted to a gear wheel which is a part of the base of the jack. This gear wheel engages a pinion gear which is manually turned by means of a handle or crank. The screw jack is widely used as a lightweight vehicle jack. Another form of jack widely used for this purpose is the scissors jack.
The jack is usually mounted on a flat floor or ground engaging base with the post of the jack mounted perpendicularly to this base. One difficulty that has been encountered with the usual jack of the above type is that the support surface is not always level and this may result in jamming of the elevating portion of the jack within the encasing elevator tube.
One prior system for solving the above problem is described in Larson et al, U.S. Pat. No. 1,810,667 which describes a ball and socket joint between base members with fastening bolts and springs positioned at the corners of the base. These springs and bolts permitted a tilting movement about the ball and socket joint.
Another tilting system for vehicle jacks is described in British Pat. No. 817,338, published July 29, 1959. That patent shows the use of rubber blocks as resilient means but the jack is designed for tilting only about one lateral axis.
It is the object of the present invention to provide an improved design of vehicle jack which is resiliently tiltable in at least 4 ways.